/*
 * $Id: ShadingColorHighlighter.java 3100 2008-10-14 22:33:10Z rah003 $
 *
 * Copyright 2006 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package org.jdesktop.swingx.decorator;

import java.awt.Color;
import java.awt.Component;

/**
 * Experimental replacement of HierarchicalColumnHighligher. Darkens the
 * component's background.
 * 
 * @author Jeanette Winzenburg
 */
public class ShadingColorHighlighter extends ColorHighlighter {

	/**
	 * Instantiates a Highlighter with null colors using the default
	 * HighlightPredicate.
	 * 
	 */
	public ShadingColorHighlighter() {
		this(null);
	}

	/**
	 * Instantiates a Highlighter with null colors using the specified
	 * HighlightPredicate.
	 * 
	 * @param predicate
	 *            the HighlightPredicate to use.
	 */
	public ShadingColorHighlighter(HighlightPredicate predicate) {
		super(predicate, null, null);
	}

	/**
	 * Applies a suitable background for the renderer component within the
	 * specified adapter.
	 * <p>
	 * 
	 * This implementation applies its a darkened background to an unselected
	 * adapter. Does nothing for selected cells.
	 *
	 * @param renderer
	 *            the cell renderer component that is to be decorated
	 * @param adapter
	 *            the ComponentAdapter for this decorate operation
	 */
	@Override
	protected void applyBackground(Component renderer, ComponentAdapter adapter) {
		if (adapter.isSelected())
			return;
		// PENDING JW: really? That would be applying a absolute color, instead
		// of shading whatever the renderer has.
		Color background = getBackground();
		if (background == null) {
			background = renderer.getBackground();
		}
		// Change to the following
		// Color background = renderer.getBackground();
		if (background != null) {
			renderer.setBackground(computeBackgroundSeed(background));
		}
	}

	protected Color computeBackgroundSeed(Color seed) {
		return new Color(Math.max((int) (seed.getRed() * 0.95), 0), Math.max((int) (seed.getGreen() * 0.95), 0), Math.max(
				(int) (seed.getBlue() * 0.95), 0));
	}

}
